On average, listings lease in the $10's per square foot per year. The Richardson submarket is going through a decrease in rates. In the last 3 months, the median rate fell $1 per sqft per year. That's a 6% decrease in rent.
Compared to the rest of the DFW Metroplex market, the Richardson region has smaller rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 99 listings have been listed, so you'll want to check back regularly for new listings. About 8% of the listings in the Richardson are subleases, so you will probably need to consider the implications of signing a direct lease with the building. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,190 sqft. Most buildings in this region are approximately 2 floors. Most buildings in this area were built in 1985 and are Class B.